Method and apparatus for constructing subaqueous tunnels.



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B. DOUGLAS.

THE Ncmus PETERS cen, WASHINGTON, n. c.

ME'IHOD AND APPARATUS FOR -GGNSTRUGTING SUBAQUEOUS TUNNBLS.

APPLICATION FILED HAY 26, 1908.

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PATENTED MAY 26, 1908.

METHOD AND APPARATUS POR GONSTRUCTING SUBAQUEOUS TUNNELS.

APPLIUATION FILED MAY-26. 1906.

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[IIAn UG'LAS- No. 888,790. PATENTBD MAY 26, 1908. B.n0UGLAs. METHOD AND APPARATUS PoR coNsTRUGT1NG-sUBAQUBoUs TUNNELS.

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No. 888,790. PATLENTBDV MAY ze, 1908;.

vB. DOUGLAS.

METHOD AND APPARATUS FOR GONSTRUGT'ING. SUBAQUEOUS TUNNELS.

, 2 l APPLICATION FILED MAY 6, 1906 6 SHEETS-BREST 4' wlw-misses INVENTOR @wymfm 1H: Narzms versus cqL, wasmyamw. D. cA

No. 888,790. l PATENT-DD MAY 26, 1908.

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METHOD AND APPARATUS FOR CDNSTDUGTIDG sUBAQUDoUs .TUNNDLS- N L 2a 1 APPLIoATlo PI DD MAY 90e BHBETSSHEET 5.

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BENJAMIN DOUGLAS, OF GROSSE ILE, MICHIGAN.

METHOD AND .APPARATS FOR CONSTRUCTING SUBAQ'UEOUS TUNNELS Specification of Letters Patent.

Patented May 26, 1908.

Application led May 26, 1906. Serial No. 318,849.

To all whom it may concern:

Be it known that I, BENJAMIN DOUGLAS, a citizen of the United States of America, residing at Grosse Ile, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Methods and Apparatus for Constructing Subaqueous Tunne s, of which the following is a specification, reference being had therein to the accompanying drawings.

It is the obj ect of the invention to simplify the construction of a tunnel, and to rovide means whereby it may be built direct y upon a permanent foundation.

To this end, the invention consists, first, in the novel method of the construction employed, second, in the peculiar construction of the apparatus, and particularly the protecting shield, as more fully hereinafter set forth.

In the drawings, Figure 1 is a longitudinal section through a portion of the tunnel in the process of construction and the protecting tunnel shield Fig. 2 is a cross section on line x-x in Fig. 1; Fig. 3 is a cross section on line y-fg,- and Figs. 4 and 5 illustrate alternative forms of air joints between the shield and the tunnel, and Fig. is an enlarged longitudinal section through the shield and a portion of the tunnel under construction.

In constructing a tunnel by my improved method, I employ a protecting shield, which is open at the bottom, the water being eX-v cluded by pneumatic pressure. This permits of preparing the foundation within the shield, as well as the building of the super- Furthermore, the shield itself may be supported upon a track over which it is advanced and the building of this track in front of the point of support may be also performed within the shield.v

To facilitate the building, the lower and upper parts of the tunnel are preferably constructed in different compartments of the protecting shield, which are separated from each other by an air lock. The compartment in which the lower part is constructed is of lesser height than the compartment for the upper part, and the air pressure is higher so as to displace the water to a lower level. In the other compartment a higher water level is maintained, and consequently a lesser air pressure is necessary to balance the hydrostatic pressure.

As illustrated in Figs. 1, 2 and 3, A is a shield of substantially rectangular cross section, which is open at the bottom, and is divided by cross partitions B into a forward compartment C, and a rear compartment D. The forward compartment is of sufficient height to permit of the construction of the foundation, and preferably also a portion of the side walls of the tunnel, but is only a portion of the height ofthe rear compartment, in which the superstructure is completed. This reduced height -of the forward compartment diminishes the displacement and reduces the loading necessary to balance the hydrostatic ressure.

E is an air loc; in connection with partition B through which the material and workmen may pass from one compartment to the other. An air tight joint is maintained between the partition B and the portion of the tunnel constructed in the forward compartment by suitable means, such as illustrated in Figs. 4 and 5. In the former a layer of clay is packed between the edge of the partition and the structure, while in Fig. 5, a pneumatic cushion F seals the joint. Both of these constructions permit of advancing the shield from time to time after the completion of a section of the construction therein, and maintaining the air seal during advancement.

For guiding and supporting the shield, a

track is preferably constructed and this is4 built just inside the shield, adjacent to the side Walls thereof. A foundation for the track may also be prepared preferably by driving short piles within and at the forward end of compartment C, and then laying u on these piles stringers H, to which the ra' s I are secured. J are track wheels upon the shield, engaging the rails I, and which are of sufficient distance from the forward endof the shield to permit of constructing the track in advance, as just described.

The rear compartment D is provided with a rear wall K, which iits about the outside face of the tunnel superstructure, and eX- tends downward to slightly below the water level which is'to be maintained. The joint between this wall and the tunnel wall may be formed as illustrated in Figs. 4 and 5, or by any other suitable means.

The advancement of the shield may be accomplished by the use of hydraulic jacks when necessary, but, inasmuch as the internal air pressure in the shield necessary to dejacks.

providing an upward extension O at the formatic vqueous tunnels, which consists in building 'the same within an open bottom shield, in 1 press the water .level is partly unbalanced, a strong pressure will be exerted to pro el forward the shield. I therefore preferab y provide a series of cables L, which are attached at their forward ends to the shield, and eX- tend backward through the tunnel, being suitably anchored at the rear ends, as by attachment to a bulkhead M thus serving to restrain the forward movement of the shield. Means are also provided for paying out these cables as necessary to the advance of the shield, such, for instance, as hydraulic jacks \l.

The construction being as described, in operation, the building of the foundation and a portion of the side walls of the tunnel, and the construction of the track, are performed in the compartment C, and the superstructure is built in the compartmentD upon apreviously constructed portion of the foundation. lVhene'ver necessary, the shield is advanced by the operation of the hydraulic In the compartment C, the water level is preferably maintained near the lower edge of the shield, so that all of the space is available for work. On the other hand, in the compartment D the water level may be maintained only slightly below the upper edge of the side walls constructed in the compartmentC, the foundation and the lower portion of said side walls being submerged.

The object in dividing the shield into two compartments in which water levels of different heights are maintained by pneumatic pressure is that the unbalanced pneumatic pressure is very greatly reduced over a construction having a single compartment. This diminishes the strength necessary in the cables or other devices employed for holding back the shield. By making the forward compartment of lesser height than the rear compartment the displacement of the shield is diminished, and furthermore there is a reduction in the side pressure to which the shield is subjected where the tunnel is laid transversely across a flowing stream.

Where the character of the soil requires it, piles may be driven within the shield for supporting the entire foundation as well as the tracks. The operation may be facilitated by ward end of the shield, in which the driving mechanism, such as l), may be located, and this also permits of employing piles of greater length.

What I claim as my invention is:

1. The method of constructing subaqueous tunnels, which consists in building the same within an open bottom shield, and in advancing said shield and depressing the water level therein by an unbalanced pneuressure.

2. T e method of constructing suba- 4to control the forward movement thereof.

3. The method of building subaqueous tunnels, which consists in progressively constructing the tunnel within an open bottom shield, maintaining within said shield an unbalanced pneumatic pressure to advance the same and depress the water level therein, in applying a restraining force to normally hold said shield from forward movement, and in periodically relieving said restraining force to permit the advancement of the shield.

4. The lmethod of building subaqueous tunnels, which consists in progressively constructing the tunnel within an open bottom shield telescopically engaging the completed portion of the tunnel, in maintaining a pneumatic pressure within the tunnel and shield sufficient to advance the shield and to depress the water level therein, and in yieldably securing said shield to control the forward movement thereof.

5. The method of building subaqueous tunnels, which consists in progressively constructing the same in an' open bottom multicompartment shield telescopically engaging the completed portion of the tunnel, in .maintaining within the forward compartment of said shield a pneumatic ressure sufficient to depress the water leve for the construction of the foundation portion of the tunnel, and in maintaining a lesser pneumatic pressure in a succeeding compartment for the construction of the upper portion of the tunnel.

6. The method of constructing tunnels, which consists in driving a double series of piles within an open bottom shield adjacent to opposite sides thereof, laying tracks upon said piles and building a tunnel foundation between said tracks, and in advancing said shield support on said tracks.

7. The method of constructing tunnels, which consists in successively advancing an open bottom tunnel shield, having a plurality of separate compartments, in maintaining depressed water levelswithin said compartments at different elevations, in building the foundation and a portion of the side walls of the tunnel within the compartment having the lowest level directly upon the supporting bed, and in building a superstructure in a compartment having a higher water level.

S. The method of forming subaqueous tunnels, which consists in progressively constructing a tunnel in an open bottom multicompartment shield telescopically engaging the completed portion of the tunnel, in maintaining in the forward compartment of said shield pneumatic pressure to depress the water level sufficiently to permit of constructing the foundation portion of the tunnel, in maintaining in a succeeding compartment a lesser unbalanced pneumatic pressure suflicient to advance the shield, and in applyinga restraining force to said shield for controlling its forward movement.

9. A tunnel shield comprising a plurality of air locked open bottom compartments and means for pneumatically maintaining depressed water levels at different elevations in the two compartments.

10. A tunnel shield comprising a plurality of compartments air locked from each other and of different heights, and means for maintaining diiferent depressions of the water level within said compartments.

11. An apparatus for constructing subaqueous tunnels comprising an open bottom shieldhaving a plurality ofiair locked comartments therein, a portion of said shield forming the rear com artment, being telescopically engaged wit a completed portion of the tunnel, and the portion of the shield forming the forward compartment being telescopically engaged with an incomplete advance portion of the tunnel.

12. An apparatus for constructing tunnels comprising an open bottom shield, means for subjecting said shield to an unbalanced pneumatic pressure tending to propel same forward, and means for yieldingly resisting this forward pressure to permit advancement of the shield.

13. In an apparatus for constructing tunnels, the combination of an open bottom shield, means for subjecting said shield to an unbalanced pneumatic pressure tending to propel same forward, means for yieldingly resisting the forward movement of said shield, and controlling means whereby the advancement of the shield is permitted.

14. The method of building subaqueous tunnels, which consists in progressively constructing the tunnel in an open bottom multicompartment shield and in maintaining different pneumatic pressures in the diiferent compartments of said shield to variously depress the water leve'l therein.

In testimony whereof I affix my signature in presence of two witnesses.

BENJAMIN DOUGLAS.

Witnesses:

JAMES P. BARRY, EDwAnDs AULT. 

